X-rays can be generated by directing ultra-fast, high-power laser pulses onto one or more noble gases, such as helium. Simply directing laser pulses onto a noble gas typically results in highly divergent X-rays, meaning the X-rays travel in scattered directions. To generate a collimated beam in which X-rays travel in substantially the same direction, laser pulses are typically directed onto noble gas within a reflective tube.
In some approaches, gas is pumped at very low pressure into a reflective tube. Unfortunately, these approaches often result in lower-energy X-ray outputs, which typically cannot propagate significant distances through the atmosphere. Higher-energy X-ray outputs can be achieved by pumping gas at higher pressures into a reflective tube. However, these approaches typically require a higher flow rate of gas from one or more gas canisters. In various military and commercial applications, it is not possible or desirable to use a large amount of space for storing gas canisters.